JP4747186B2 - Composite wet etching method of laminated film - Google Patents

Description

  The present invention relates to a multilayer wet etching method for a multilayer film, and more particularly, to a multilayer wet etching method for a multilayer film in which a multilayer film composed of a plurality of films having different film qualities is collectively etched by combining a plurality of types of wet etching techniques. .

  In the manufacturing process of a liquid crystal display device or a semiconductor device, an etching process is indispensable when patterning a thin film. The wet etching of a thin film is characterized by so-called side etching that is excessively etched not only from the surface of the thin film but also from the periphery of the thin film, making it difficult to obtain a uniform shape of the thin film after etching. In particular, extremely high etching accuracy is required in wiring patterning by wet etching when forming a wiring made of a metal material. This is because when the patterning shape varies due to poor side etching accuracy, the electrical characteristics of the device are seriously affected.

  In addition, with the recent increase in the number of liquid crystal display devices and semiconductor devices, the effect of the step difference in the lower layer pattern on the coverage characteristics of the upper layer pattern with respect to the lower layer pattern is increasing. In particular, in wiring pattern etching, to maintain good coverage characteristics of the upper layer pattern, to ensure the dielectric breakdown voltage of the interlayer insulating film between the upper and lower layers, or to ensure normal conduction of the upper layer metal wiring, and further to the upper layer metal In order to avoid the occurrence of defects in the protective film that covers the wiring and to ensure reliability, so-called taper etching that provides a slope on the etched surface is one of the important factors in wet etching when patterning the lower layer wiring. It has become.

  In order to achieve this purpose, wet etching on a single wiring material (single layer film) requires the use of chemical solution permeation between resist / wiring materials by adjusting the chemical composition or controlling resist adhesion. There are many.

FIG. 10 shows an outline of a general wet etching process conventionally used.
As shown in FIGS. 10A and 10B, after the substrate 1 to be processed is carried into the etching tank 2 by the substrate transport roller 9, the etching process 2a by a single method is performed on the substrate 1 to be processed. A wet etching process such as immersion etching (static wet etching using a static chemical solution) for immersing a substrate in a chemical solution or spray etching (dynamic wet etching using a dynamic chemical solution) for spraying a chemical solution to a substrate is performed, A part of the thin film formed on the processing substrate 1 is etched.

Subsequently, the cleaning process 3 a is performed after the substrate 1 to be processed is transported to the water washing tank 3 to remove the chemical solution (etching solution) on the substrate 1 to be processed, and the drying process is performed after the substrate 1 is transported to the drying tank 4. 4a is performed, the washing water on the substrate 1 to be processed is removed, and the thin film is subjected to wet etching to perform patterning.
An apparatus used for a wet etching process by a conventional spray etching method is disclosed in Patent Document 1.

Further, as a conventional etching method for a single layer film, Patent Document 2 discloses a wet etching method in which a spray etching method and an immersion etching method are combined and the spray etching method and the immersion etching method are performed in different etching apparatuses. ing.
JP-A-57-094572 Japanese Patent Laid-Open No. 08-158069

However, when the conventional wet etching method is used for a laminated film, the following problems occur.
That is, in the case of etching the laminated film with the same chemical solution, generally the etching property (etching rate) differs for each wiring material. Further, even in the same chemical solution and the same wiring material, the etching property varies depending on the etching method.

For this reason, when etching processing of a plurality of laminated wiring materials (laminated films) is performed by a single method in the same manner as etching of a single layer film, the etching rate of the lower layer film is changed according to the etching rate difference of each film. When the etching rate is higher than this, side etching of the lower layer film occurs excessively than side etching of the upper layer film, and an overhang shape in which the upper layer film protrudes like a bowl from the lower layer film may occur. This shape further deteriorates the coverage of the film laminated on the upper layer and causes a structural defect in the upper layer film.
In this case, in order to eliminate the difference in etching rate between different wiring materials, there is a method of controlling the taper shape by using two types of chemicals with different etching properties. Is not easy.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a composite wet etching method for a laminated film that can perform batch etching while controlling the amount of side etching of the laminated film.

To achieve the above object, a first configuration of the invention, on a substrate, least also, the first film and the laminated film and the second film is formed by this order or sequentially formed in the reverse order When the relationship between the etching rates of the first film and the second film is a dynamic wet etching method using a chemical solution containing phosphoric acid, acetic acid and nitric acid, the etching rate of the Al film is Mo. On the other hand, when applying the static wet etching method using the chemical solution having the same composition, the etching rate of the Mo film is larger than that of the Al film. the laminated film substantially similar to the relationship between the etching rate and, by combining a plurality of types of wet etching techniques, relates to a wet etching process for etching at once, to the plurality of types of wet-etching technique A dynamic wet etching method for etching the laminated film until the substrate starts to be exposed by the dynamic chemical solution, and a static wet etching method for subsequently etching the laminated film with the static chemical solution, The chemical liquid used in the wet etching technique and the chemical liquid used in the static wet etching technique are chemical liquids having the same composition containing phosphoric acid, acetic acid and nitric acid.

The second configuration of the invention, on a substrate, least also the first film and the second film is a laminated film formed by this order or sequentially formed in the reverse order, the first When the dynamic wet etching method is applied using a chemical solution containing phosphoric acid, acetic acid, and nitric acid, the etching rate of the Al film is higher than that of the Mo film. On the other hand, when the static wet etching method is applied using the chemical solution having the same composition, the etching rate of the Mo film is larger than that of the Al film, and the relationship between the etching rate of the Al film and the Mo film. in the laminated film substantially similar to, a combination of a plurality kinds of wet etching techniques, relates to a wet etching process for etching at once, to the plurality of types of wet etching techniques, the substrate static chemical At least a static wet etching technique for etching the laminated film until it starts to be exposed and a dynamic wet etching technique for subsequently etching the laminated film with a dynamic chemical solution are used and used in the static wet etching technique The chemical solution and the chemical solution used in the dynamic wet etching method are characterized by having the same composition containing phosphoric acid, acetic acid and nitric acid.

  According to the configuration of the present invention, the dynamic wet etching method and the static wet etching method are used for a laminated film including two or more types of films each having a difference between forward and reverse etching rates. In combination with a typical wet etching technique, each side of the etching process can be performed to control the amount of side etching of each laminated film and to realize the patterning of the laminated film having an excellent film edge shape after etching. .

First, the outline of the wet etching process which is the best embodiment of the present invention will be described.
As shown in FIGS. 11A and 11B, after the substrate 5 to be processed is carried into the etching tank 6 by the substrate transport roller 10, the substrate 5 is spray-etched (dynamic movement using a dynamic chemical solution). The etching process 6a (corresponding to “Etching I” in FIG. 11B) such as a typical wet etching technique) or immersion etching (a static wet etching technique using a static chemical solution) is performed to form the substrate 5 to be processed. Wet etching of part of the laminated film is performed.

Further, in the same etching tank 6, an etching process 6 b (corresponding to “etching II” in FIG. 11B) different from the etching process 6 a such as immersion etching or spray etching is performed on the substrate 5 to be processed. The laminated film formed on the substrate 5 is patterned by wet etching.
Subsequently, after the substrate to be processed 5 is carried into the water rinsing tank 7, the cleaning process 7 c is performed to remove the chemical solution (etching solution). And wash water is removed.

  That is, according to the embodiment of the present invention, the etching process 2a in FIG. 10B showing the conventional process is replaced with the first etching process 6a (etching I in FIG. 11B showing the wet etching process according to the present invention). ) And the second etching step 6b (etching II), and the first etching step 6a and the second etching step 6b are combined to perform a batch etching method.

  In this embodiment, the dynamic wet etching technique is, for example, a technique (spray etching) in which a chemical solution is jetted toward a laminated film formed on a substrate to perform etching (spray etching). For example, a technique in which a substrate on which a laminated film is formed is immersed in a chemical solution to perform etching (immersion etching), or a method in which a chemical solution is applied onto the laminated film on the substrate to perform etching (paddle etching). .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1

First, a first embodiment of the present invention will be described.
FIG. 1 is a conceptual diagram showing the configuration of a wet etching apparatus 155 according to the first embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a laminated film formed on the substrate 11 to be processed for explaining the operation of the first embodiment of the present invention. The substrate 11 to be processed is in the wet etching apparatus 155. Wet etching process. Note that the laminated film shown in FIG. 2 is used as a wiring pattern in a liquid crystal display device.

First, as shown in FIG. 1, an outline of the configuration of the wet etching apparatus 155 will be described.
As shown in the figure, the wet etching apparatus 155 according to this example includes an etching tank 81, a water washing tank 82, and a drying tank 83.
The etching tank 81 includes a transport roller 12, an etching spray nozzle 13, an air knife 14, a chemical tank 17, a pipe 15, a pump 16, a dry air tank 20, a carry-in port 21, and a carry-out port. 25.
The washing tank 82 includes the transport roller 22, the pure water tank 19, the pure water spray nozzle 18, the drain pipe 23, the carry-in port 26, and the carry-out port 27.
Further, the drying tank 83 includes a transport roller 35, a dry air tank 30, a drain pipe 24, an air knife 36, a carry-in port 28, and a carry-out port 29.

Next, the structure of the laminated film formed on the to-be-processed substrate 11 is demonstrated.
As shown in the cross-sectional view of FIG. 2A, an Al (aluminum) film 32 is deposited on the glass substrate 31 to a thickness of about 100 nm by, for example, sputtering, and then Mo (molybdenum) is deposited on the Al film 32. ) A film 33 is deposited to a thickness of about 70 nm by sputtering, for example, and a resist film 34 is patterned on the Mo film 33 in a wiring pattern. A plan view of this state as viewed from above the resist film 34 is shown in FIG .

Next, the difference in the etching rate depending on the chemical composition when the laminated films 32 and 33 are etched will be described.
When the laminated films 32 and 33 are etched by each spray etching method (dynamic wet etching method using a dynamic chemical solution) and paddle etching method (static wet etching method using a static chemical solution) alone, the following composition is provided. By the chemical solution, the following etching rate magnitude relationship is obtained for the Mo film 33 and the Al film 32.

As a typical chemical composition, for example, when phosphoric acid is 79.0%, acetic acid is 3.2%, and nitric acid is 0.5%, the relationship between the etching rate of the Mo film 33 and the Al film 32 is as follows. Become.
In the case of spray etching, the etching rate of the Al film 32 is larger than the etching rate of the Mo film 33. In the case of paddle etching, the etching rate of the Mo film 33 is larger than the etching rate of the Al film 32. is there.

  The etching rate when each spray etching or paddle etching with this chemical solution is performed individually is 166 nm for the Mo film 33 and 416 nm for the Al film 32 in the case of the spray etching process, and in the case of the paddle etching process in the case of the paddle etching process. The Mo film 33 is 250 nm and the Al film 32 is 166 nm.

Next, the operation of the wet etching apparatus 155 and the etching operation of the laminated films 32 and 33 on the substrate 11 to be processed will be described.
As shown in FIG. 1, a pump 16 is supplied from a chemical solution tank 17 through a pipe 15 to the surface of the substrate 11 to be processed which is sent to the etching tank 81 by the transport roller 12 from the carry-in entrance 21 of the etching tank 81. A chemical solution (etching solution) is sprayed from a plurality of stages of etching spray nozzles 13 for a predetermined time, for example, for 25 seconds to perform the spray etching process on the substrate 11 to be processed.

  Next, as shown in FIG. 3A, the film end (side) of the lower Al film 32 is set back with respect to the upper Mo film 33 due to the above etching rate by spray etching. A part of the film edges of the laminated films 32 and 33 outside the resist pattern 34 are side-etched all at once, and the injection of the chemical solution is stopped until the glass substrate 31 starts to be exposed. At that time, since the chemical solution remains uniformly on the substrate 11 to be processed, the etching of the stacked films 32 and 33 further proceeds by allowing the substrate 11 to be left in the etching tank 81 as it is for 70 seconds, for example. Paddle etching is performed.

  Further, as shown in FIG. 3B, the paddle etching process causes the film edge of the upper Mo film 33 protruding from the lower Al film 32 to recede due to the above-described etching rate, and the distance between the film edges of both films Approaches. Finally, as shown in FIG. 3B, the paddle etching is finished when the film ends of the laminated films 32 and 33 reach a time in which the shape of the film ends becomes a forward taper. The chemical solution remaining on the surface of the substrate to be processed 11 is washed away in the water washing tank 82, and the progress of etching is stopped.

  That is, as shown in FIG. 1, pure water supplied from the pure water tank 19 from the cleaning spray nozzle 18 is sprayed onto the substrate 11 after the etching process in the water rinsing tank 82, and the predetermined time is, for example, 200 seconds. The chemical solution after washing is drained through the drain pipe 23. After cleaning, the substrate 11 to be processed is carried out from the carry-out port 27 of the water washing tank 82 and carried into the drying tank 83 from the carry-in port 28.

  Further, in the drying tank 83, pure water on the surface of the substrate to be processed 11 is removed by blowing dry air supplied from the dry air tank 30 to the substrate to be processed 11, and the surface of the substrate 11 to be processed is dried. The removed cleaning liquid is drained from the drain pipe 24. After completion of the drying process, the substrate 11 to be processed is carried out from the carry-out port 29 of the drying tank 83.

  In this embodiment, the order of spray etching and paddle etching may be interchanged. When performing the paddle etching first, if the etching apparatuses 81 to 83 have a function (pre-wet) for applying a chemical solution to the surface of the substrate 11 to be processed as a pre-treatment for the purpose of improving wettability, pre-wet Paddle etching with a chemical solution deposited on the substrate 11 to be processed can be performed by the function.

In this case, the operation of the wet etching apparatus 155 is as follows.
For example, after the paddle etching process for about 70 seconds, the substrate 11 to be processed is spray-etched by spraying from the etching spray nozzle 13 for about 25 seconds, for example. After a predetermined spray etching processing time has elapsed, the injection of the chemical solution onto the substrate 11 to be processed is stopped. By blowing out dry air supplied from the dry air tank 20 from the air knife 14, the chemical solution on the substrate 11 to be processed is removed, and the etching process is terminated. The substrate 11 to be processed is carried out from the carry-out port 25 of the etching tank 81 and carried into the water washing tank 82 from the carry-in port 26.

In this embodiment, when the stacking order of the films 32 and 33 is reversed, that is, the Mo film 33 is deposited on the glass substrate 31 by, for example, sputtering, and then the Al film 32 is deposited on the Mo film 33 by, for example, sputtering. Even when it is deposited by the above, it can be carried out.
In addition, since the method according to this embodiment uses an apparatus of a general spray etching method as it is, by finding a combination order of etching processing methods suitable for the material of the laminated film and an appropriate processing time, for example, As described above, when the stacking order of the Al film 32 and the Mo film 33 shown in FIG. 2 is reversed, it is possible to change the processing order of the spray etching and the paddle etching correspondingly. There is an advantage that can be implemented without remodeling.
As described above, spray etching and paddle etching can be performed collectively in wet etching of a two-layer film made of two kinds of films of different materials.

Embodiment 2

Next explained is the second embodiment of the invention.
An example in which a spray etching process and a paddle etching process are performed on the three-layered film formed on the target substrate 40 illustrated in FIG. 4 by the wet etching apparatus 156 illustrated in FIG. 5 will be described.
In FIG. 4, the Al film 43 is sandwiched between Mo films 42 and 44, and the Al film 43 is sandwiched between Mo films 42 and 44.
As shown in the drawing, the details of the substrate 40 to be processed include a Mo film 42 on the glass substrate 41 of about 70 nm, an Al film 43 on the Mo film 42 of about 100 nm, and a Mo film 44 on the Al film 43 of about 70 nm. In either case, the film is formed by sputtering, for example, and a resist film 45 is patterned on the Mo film 44 in a wiring shape.

Next, the configuration of the wet etching apparatus 156 will be described.
As shown in FIG. 5, the wet etching apparatus 156 includes an etching tank 121, a water washing tank 122, and a drying tank 123.
The etching tank 121 includes a transport roller 37, an etching spray nozzle 150, an air knife 38, a chemical solution tank 48, and a dry air tank 39.
And a carry-in port 46 and a carry-out port 47.
Other configurations of the etching tank 121, the water washing tank 122, and the drying tank 123 are the same as those of the etching tank 81, the water washing tank 82, and the drying tank 83 in the wet etching apparatus 155 shown in FIG. is there.

  When the substrate to be processed 40 including the laminated films 42, 43, and 44 is etched by each spray etching method and paddle etching method alone, the Mo films 42, 44 and the Mo film 42, 44 are formed using a chemical solution having the same composition as that of the first embodiment. For the Al film 43, the same magnitude relationship of the etching rate as in the first embodiment is obtained.

Next, when an etching process according to this embodiment is performed on the substrate to be processed 40 including the laminated films 42, 43, and 44, the following is performed.
First, in the wet etching apparatus 156 shown in FIG. 5, the substrate to be processed 40 shown in FIG. 4 is carried into the etching tank 121 through the carry-in port 46, and is etched by spray etching. The spraying time of the chemical solution from the etching spray nozzle 150 onto the substrate to be processed 40 is about 36 seconds.

  At this time, as shown in FIG. 4B, due to the same etching rate relationship as in the first embodiment, the film end of the Al film 43 in the intermediate layer receded from the upper and lower Mo films 42 and 44. It becomes a state. Further, since the side etching of the upper Mo film 44 proceeds until the lower Mo film 42 is exposed, the end of the upper Mo film 44 is also set back from the end of the lower Mo film 42. The injection of the chemical solution is stopped until the laminated film outside the resist pattern 45 is etched and the glass substrate 41 starts to be exposed.

Thereafter, similarly to the first embodiment, the etching of the laminated films 42, 43 and 44 is further advanced by performing paddle etching in the etching tank 121. At this time, due to the above-described etching rate relationship, the upper and lower Mo films 42 and 44 protruding from the intermediate Al film 43 are retracted, and the distance between the film ends approaches each other.
Finally, as shown in FIG. 4C, the film ends of the entire laminated films 42, 43 and 44 have a forward tapered shape.
After completion of the wet etching, the substrate to be processed 40 removes the chemical solution in the water washing tank 122 and removes pure water in the drying tank 123 as in the first embodiment.

When a difference in etching rate is obtained by a single etching method, such as the upper and lower Mo films 42 and 44, this embodiment can be applied regardless of the order of the stacked films, the number of stacked films, and the material of the films. Is possible.
As described above, in the wet etching of the three-layer film composed of two kinds of films of different materials, the spray etching and the paddle etching can be performed collectively, and the processing order of the spray etching and the paddle etching can be changed. It is possible to perform wet etching according to the film quality of the three-layer film.

Embodiment 3

Next explained is the third embodiment of the invention.
In this embodiment, the paddle etching in the second embodiment is replaced with immersion etching. A wet etching apparatus used in the third embodiment is shown in FIG.

FIG. 7 shows the substrate 51 to be processed. The configuration of the laminated films 131, 132, and 133 including the three layers shown in the figure is the same as that of the second embodiment.
That is, as shown in FIG. 7A, the cross-sectional structure of the substrate 51 to be processed is such that the Mo film 131 is about 70 nm on the glass substrate 130, the Al film 132 is about 100 nm on the Mo film 131, and the Al film 132 is on. The Mo film 133 is formed to have a thickness of about 70 nm, for example, by sputtering, and a resist film 134 is patterned on the Mo film 133 in a wiring shape.

Next, the configuration of the wet etching apparatus 157 when the substrate to be processed 51 is subjected to the spray etching process and the immersion etching process will be described.
As shown in FIG. 6, the wet etching apparatus 157 according to this example includes an etching tank 84, a water washing tank 85, and a drying tank 86.

The etching tank 84 includes a transport roller 52, an etching spray nozzle 53, an air knife 54, a chemical tank 58, a pipe 56, a pump 57, a dry air tank 55, a carry-in port 60, and a carry-out port. 61.
The washing tank 85 includes a transport roller 52, a pure water tank 63, a pure water spray nozzle 62, a drain pipe 68, a carry-in port 69, and a carry-out port 70.
Further, the drying tank 86 includes a transport roller 52, a dry air tank 64, a drain pipe 66, an air knife 49, a carry-in port 71, and a carry-out port 67.

Next, the operation when the substrate to be processed 51 is etched by the wet etching apparatus 157 will be described.
As shown in FIG. 6, the chemical solution supplied from the chemical solution tank 58 via the pipe 56 and the pump 57 is etched on the surface of the substrate 51 to be processed which is sent from the carry-in entrance 60 to the etching tank 84 by the conveyance roller 52. It sprays from the spray nozzle 53 and performs the spray etching process for 36 seconds as a predetermined time.

  When the laminated films 131, 132, and 133 are etched by each spray etching method and immersion etching method alone, the Mo films 131, 133 and the Al film 132 are applied to the Mo films 131, 133, and the Al film 132 by a chemical solution having the same composition as that of the first embodiment. The same etching rate relationship as in the first embodiment can be obtained.

  That is, as shown in FIG. 7B, by spray etching, the film end of the Al film 132 of the intermediate layer is formed on the upper and lower Mo films 131 and 133 by the relationship of the etching rates of the laminated films 131, 132, and 133. On the other hand, it will be in a retreated state. Further, since the side etching of the upper Mo film 133 proceeds until the lower Mo film 131 is exposed, the end of the upper Mo film 133 is also retracted from the end of the lower Mo film 131. The injection of the chemical solution is stopped until the laminated film outside the resist pattern 134 is etched and the glass substrate 130 starts to be exposed.

  Next, the loading / unloading ports 60 and 61 are closed by operating the shutter 65 of the etching tank 84, and the chemical liquid 59 same as that at the time of spray etching is filled in the etching tank 84 to the extent that the substrate 51 to be processed is sufficiently immersed. For example, the immersion etching is performed for about 170 seconds.

  By performing the immersion etching, the etching of the laminated films 131, 132, and 133 is further advanced. That is, due to the etching rate of the three-layer film, the upper and lower Mo films 131 and 133 protruding with respect to the intermediate Al film 132 are retracted, and the film edge distance between them approaches. That is, as shown in FIG. 7C, the film ends of the entire laminated films 131, 132, and 133 have a forward tapered shape.

  Next, in the water rinsing tank 85, pure water supplied from the pure water tank 63 is sprayed from the cleaning spray nozzle 62 onto the substrate 51 to be processed after the etching process, and cleaning is performed for a predetermined time, for example, 200 seconds. The chemical solution remaining on the processing substrate 51 is removed. After the removal, the chemical solution is drained from the drain pipe 68, the substrate 51 to be processed is unloaded from the washing tank 85 through the carry-out port 70, and carried into the drying tank 86 through the carry-in port 71.

Further, the dry water supplied from the dry air tank 64 in the drying tank 86 is blown to the substrate 51 to be processed, thereby removing the pure water remaining on the surface of the substrate 51 to be processed. 66 is discharged. After completion of the drying process, the substrate 51 to be processed is unloaded from the unloading port 67 of the drying tank 86.
Since immersion etching is performed in a still liquid as in the case of paddle etching, when the same chemical solution is used, an etching property similar to that of paddle etching can be obtained for each film.

Even if the laminated film in the substrate 51 to be processed in the third embodiment is a two-layer film similar to the first embodiment, it can be applied without any problem. Therefore, also in the third embodiment, the same object as that of the other embodiments is achieved.
Also in this embodiment, the order of the etching method to be carried out may be immersion etching after spray etching or spray etching after immersion etching.

  That is, when the spray etching process is performed after the immersion etching process, the injection of the chemical liquid onto the substrate 51 is stopped after the predetermined time of the spray etching process. The chemical solution 59 in the etching tank 84 is discharged to the chemical solution tank 58, and the dry solution supplied from the dry air tank 55 is sprayed from the air knife 54 to remove the chemical solution on the surface of the substrate 51 to be processed. Thereafter, the etching process is finished, and the substrate 51 to be processed is carried out from the carry-out port 61 of the etching tank 84 and carried into the water washing tank 85 through the carry-in port 69.

  As described above, in the wet etching of the two-layer film or the three-layer film made of two kinds of films having different materials, the spray etching and the paddle etching, or the spray etching and the immersion etching are collectively performed, so that each film By controlling the amount of side etching, patterning with uniform film edges of the three-layer film can be performed. Also, the order of spray etching and paddle etching or spray etching and immersion etching can be reversed, and the process window can be enlarged.

  Further, as another embodiment, in the case of a two-layer film or a three-layer film as shown in FIGS. 3 and 4, the chemical composition used in the immersion etching and the paddle etching is made different so that the immersion etching and the paddle are performed. In the case of a laminated film in which a difference in etching rate is seen between etching, an etching method combining immersion etching and paddle etching can be performed.

  Furthermore, as another embodiment, in the case of a two-layer film or a three-layer film as shown in FIGS. 3 and 4, or in the case of a three-layer film made of different materials, a chemical solution used for immersion etching and paddle etching. If there is a difference in the amount of side etching of each film between spray etching, immersion etching and paddle etching by making the composition different, an etching method combining spray etching, immersion etching and paddle etching at the same time is used. Can also be implemented.

Embodiment 4

Next explained is the fourth embodiment of the invention.
In this embodiment, a method of successively performing two different etching methods in two adjacent etching tanks will be described.
FIG. 8 is a conceptual diagram showing a configuration of a wet etching apparatus 158 that is a fourth embodiment in which spray etching and immersion etching are performed in separate etching tanks 87 and 88.

FIG. 9 shows the substrate 101 to be processed which is etched by the wet etching apparatus 158. The configuration of the laminated films 142, 143, and 144 including three layers shown in the figure is the same as that of the second embodiment.
That is, as shown in FIG. 9A, the cross-sectional structure of the substrate 101 to be processed is that the Mo film 142 is about 70 nm on the glass substrate 141, the Al film 143 is about 100 nm on the Mo film 142, and the Al film 143 is on. The Mo film 144 is formed to have a thickness of about 70 nm by sputtering, for example, and a resist film 145 is patterned on the Mo film 144 in a wiring shape.

Next, the configuration of the wet etching apparatus 157 when the substrate to be processed 101 is subjected to the spray etching process and the immersion etching process will be described.
As shown in FIG. 8, the wet etching apparatus 158 according to this example includes etching tanks 87 and 88, a washing tank 89, and a drying tank 90.

  Also, the etching tanks 87 and 88 are respectively provided with a transport roller 102, etching spray nozzles 103 and 113, air knives 104 and 114, chemical tanks 107 and 118, pipes 105 and 116, pumps 106 and 117, and dry tanks. The air tanks 108 and 119, the carry-in ports 91 and 93, and the carry-out ports 92 and 94 are configured.

The washing tank 89 includes a transport roller 102, a pure water tank 123, a pure water spray nozzle 121, a drain pipe 122, a carry-in port 95, and a carry-out port 96.
Further, the drying tank 90 includes a transport roller 102, a dry air tank 125, a drain pipe 124, an air knife 50, a carry-in port 97, and a carry-out port 98.

Next, the operation when the substrate to be processed 101 is etched by the wet etching apparatus 158 will be described.
As shown in FIG. 8, the chemical solution supplied from the chemical solution tank 107 via the pipe 105 and the pump 106 is etched on the surface of the substrate 101 to be processed which is sent from the carry-in port 91 to the etching tank 87 by the conveyance roller 102. Spraying from the spray nozzle 103 and performing a spray etching process for a predetermined time, for example, for 36 seconds.

  When the laminated films 142, 143, and 144 are etched by the spray etching technique and the immersion etching technique alone, the Mo films 142 and 144 and the Al film 143 are applied to the Mo films 142 and 144 and the Al film 143 by a chemical solution having the same composition as that of the first embodiment. The same etching rate relationship as in the first embodiment can be obtained.

  That is, as shown in FIG. 7B, by spray etching, the film end of the Al film 132 of the intermediate layer is formed on the upper and lower Mo films 131 and 133 by the relationship of the etching rates of the laminated films 131, 132, and 133. On the other hand, it will be in a retreated state. Further, since the side etching of the upper Mo film 133 proceeds until the lower Mo film 131 is exposed, the end of the upper Mo film 133 is also retracted from the end of the lower Mo film 131. The injection of the chemical solution is stopped until the laminated film outside the resist pattern 134 is etched and the glass substrate 130 starts to be exposed. That is, after the predetermined time of the spray etching process has elapsed, the spraying of the chemical liquid onto the substrate 101 is blocked by the air knife 104.

  Next, the substrate 101 to be processed is transferred to the etching tank 88 via the carry-out port 92 and the carry-in port 93, and the carry-in / out ports 93 and 94 are closed by operating the shutter 115 of the etching tank 88. In the etching tank 88, the same chemical solution 120 as that used in the spray etching is filled and immersion is performed for about 170 seconds, for example.

  Etching of the laminated films 142, 143, and 144 is further advanced by performing immersion etching. That is, due to the etching rate of the three-layer film, the upper and lower Mo films 142 and 144 protruding from the intermediate Al film 143 recede, and the film edge distance between them approaches. That is, as shown in FIG. 9C, the film ends of the entire laminated films 142, 143, and 144 are in a forward tapered shape.

  Next, in the water rinsing tank 89, pure water supplied from the pure water tank 123 is sprayed from the cleaning spray nozzle 121 onto the substrate 101 to be processed after the etching process, and cleaning is performed for 200 seconds as a predetermined time. The chemical solution remaining on the processing substrate 101 is removed. The removed chemical solution is drained from the drain pipe 122, and the substrate to be processed 101 is unloaded from the washing tank 89 through the carry-out port 96 and carried into the drying tank 90 through the carry-in port 97.

  Further, the dry water supplied from the dry air tank 125 is blown to the substrate to be processed 101 in the drying tank 90 to remove the pure water remaining on the surface of the substrate to be processed 101, and the pure water after the removal is discharged to the discharge pipe. It is discharged from 124. After completion of the drying process, the substrate 101 is unloaded from the unloading port 98 of the drying tank 90.

  As in this embodiment, the etching tank for performing two kinds of wet etching processes is separated into two etching tanks and connected in series, and the etching process is continuously performed, thereby performing the etching process in one etching process tank. Time required is dispersed, and the substrate to be processed can be efficiently supplied to the subsequent wafer process steps.

  In addition, by making the two etching tanks connected in series with each other, each etching tank is an etching tank having the same function capable of performing any etching method of spray etching, paddle etching, and immersion etching. Each combination and order of the above etching methods can be flexibly changed according to the mode of the laminated film, and the wet etching process of the laminated film can be efficiently performed.

  This embodiment is an example in which spray etching and immersion etching are performed in different etching tanks. However, spray etching and paddle etching, or paddle etching and immersion etching are respectively combined and performed in each etching tank. It is also possible.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the present invention can be changed even if there is a design change or the like without departing from the gist of the present invention. include.
For example, in this embodiment, the case where a mixed solution of phosphoric acid, acetic acid and nitric acid is used as an etching solution has been described, but depending on what the film to be processed is, how many layers the multilayer film is, or The composition ratio of the mixed solution can be appropriately changed depending on the film forming sequence of the film forming materials.

In the above-described embodiment, the two-layer film and the three-layer film have been described. However, the present invention is not limited to these, and a laminated film of four or more layers may be used. There may be.
Further, the substrate is not limited to a glass substrate, and may be a semiconductor substrate such as silicon or another substrate. The film forming material is not limited to the Al film and the Mo film, and may be a laminated film in which various metal materials, insulating film materials, and semiconductor materials are added to the Al film and the Mo film as necessary.

1 is a diagram illustrating a configuration of a wet etching apparatus according to a first embodiment of the present invention. It is a figure which shows the laminated film in the same embodiment, a resist pattern, and its sectional drawing. It is a figure which shows the etching process of the laminated film in the embodiment. It is a figure which shows the etching process of the laminated film in 2nd Embodiment of this invention. It is a figure which shows the structure of the wet etching apparatus in the embodiment. It is a figure which shows the structure of the wet etching apparatus in 3rd Embodiment of this invention. It is a figure which shows the etching process of the laminated film in the embodiment. It is a figure which shows the structure of the wet etching apparatus in 4th Embodiment of this invention. It is a figure which shows the etching process of the laminated film in the embodiment. It is the schematic which shows the conventional wet etching process. It is the schematic which shows the outline | summary of the wet etching process of embodiment of this invention.

Explanation of symbols

11, 40, 51, 101 Substrate to be processed 81, 84, 87, 88, 121 Etching tank 12, 22, 35, 37, 52
102, 112 Substrate transport roller 13, 53, 103, 113, 150 Etching spray nozzle 14, 36, 38, 49, 50, 54
104, 114 Air knife 15, 56, 105, 116 Piping 16, 57, 106, 117 Pump 17, 48, 58, 107, 118 Chemical liquid tank 18, 62, 121 Cleaning spray nozzle 19, 63, 123 Pure water tank 20, 30, 39, 55, 64
108, 119, 125 Dry air tank 21, 25, 26, 27, 28, 29
46, 47, 60, 61, 67, 69 Substrate carry-in / out port 31, 41, 130, 141 Glass substrate (substrate)
32, 43, 132, 143 Aluminum film 33, 42, 44, 131, 133
142, 144 Molybdenum film 34, 45, 134, 145 Resist film 59 Chemical solution (etching solution)
65 Shutters 155, 156, 157
158, 159 Wet etching equipment

Claims (4)

On a substrate, least also the first film and the second film is a laminated film formed by this order or sequentially formed in the reverse order, the first film and the etching rate of the second film When the dynamic wet etching method is applied using a chemical solution containing phosphoric acid, acetic acid and nitric acid, the etching rate of the Al film is larger than that of the Mo film, while the chemical solution having the same composition is used. When the static wet etching method is applied, the stacked film substantially similar to the relationship between the etching rate of the Al film and the Mo film, in which the etching rate of the Mo film is larger than that of the Al film , A wet etching method that combines multiple types of wet etching techniques to perform batch etching,
The multiple types of wet etching techniques include
A dynamic wet etching technique for etching the laminated film until the substrate starts to be exposed by the dynamic chemical solution;
Subsequently, a static wet etching method of etching the laminated film with a static chemical solution is included at least,
The compound wet etching method for laminated film, wherein the chemical solution used in the dynamic wet etching method and the chemical solution used in the static wet etching method are chemical solutions having the same composition containing phosphoric acid, acetic acid and nitric acid . On a substrate, least also the first film and the second film is a laminated film formed by this order or sequentially formed in the reverse order, the first film and the etching rate of the second film When the dynamic wet etching method is applied using a chemical solution containing phosphoric acid, acetic acid and nitric acid, the etching rate of the Al film is larger than that of the Mo film, while the chemical solution having the same composition is used. When the static wet etching method is applied, the stacked film substantially similar to the relationship between the etching rate of the Al film and the Mo film, in which the etching rate of the Mo film is larger than that of the Al film , A wet etching method that combines multiple types of wet etching techniques to perform batch etching,
The multiple types of wet etching techniques include
A static wet etching technique for etching the laminated film until the substrate starts to be exposed by a static chemical solution;
And at least a dynamic wet etching technique of etching the laminated film with a dynamic chemical solution,
The compound wet etching method for laminated film, wherein the chemical solution used in the static wet etching method and the chemical solution used in the dynamic wet etching method are chemical solutions having the same composition containing phosphoric acid, acetic acid and nitric acid .   The dynamic wet etching method is a method of performing etching by injecting a chemical solution toward the laminated film formed on the substrate, and the static wet etching method is formed by forming the laminated film. 3. The lamination according to claim 1, wherein the etching is performed by immersing the formed substrate in a chemical solution, or a method of performing etching by applying a chemical solution on the laminated film on the substrate. Compound wet etching method of film.   The laminated film has a configuration in which the first film is sandwiched by the second film, or a structure in which the second film is sandwiched by the first film. The method for complex wet etching of a laminated film according to claim 1 or 2.

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